Microbial Insecticides

Bacteria

Biopesticides based on bacteria have been used to control plant diseases, nematodes, insects, and weeds. Bacteria are present in all soils and are the most abundant micro-organisms in soil samples. Many spore forming and non-spore forming bacteria are known to be effective against a wide spectrum of insects and diseases. Among them, they might act as competitors or inducers of host resistance in plant. Some act by inhibiting growth, feeding, development or reproduction of a pest or pathogen.

The most well-known and widely used of all biopesticides are insecticides based on Bacillus thuringiensis, commonly referred to as “Bt.” Other bacteria are used for the control of plant pathogens. Certain strains of Bacillus subtilis, Bacillus pumilus, and Streptomyces spp. increase yield and prevent plant diseases by outcompeting plant pathogens in the rhizosphere, producing anti-fungal compounds, and by promoting plant and root growth.